Abstract
ABSTRACTCZT is a semiconductor material that promises to be a good candidate for uncooled gamma radiation detectors. However, to date, technological difficulties in production of large size defect-free CZT crystals are yet to be overcome. The most common problem is accumulation of tellurium precipitates as microscopic inclusions. These inclusions influence the charge collection through charge trapping and electric field distortion. The common work-around solutions are to fabricate pixelated detectors by either grouping together many small volume CZT crystals to act as individual detectors, or to deposit a pixelated grid of electrical contacts on a larger, but defective, crystal, and selectively collect charge. These solutions are satisfactory in an R&D environment, but are unsuitable for mass production and commercial development. Our modeling effort is aimed at quantifying the various contributions of tellurium inclusions in CZT crystals to the charge generation, transport, and collection, as a function of inclusions size, position, and concentration. We model the energy deposition of gamma photons in the sensitive volume of the detector using LANL’s MCNP code. The electron-hole pairs produced at the energy deposition sites are then transported through the defective crystal and collected as integral charge at the electrical contact sites using CERN’s Garfield software package. The size and position distribution of tellurium inclusions is modeled by sampling experimentally measured distributions of such inclusions on a variety of commercially-grown CZT crystals using IR microscopy and image processing software packages.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.